(n.) A blood feud; private revenge for the murder of a kinsman.

acrimony altercation animosity animus argument avengement bad blood bicker bitter feeling bitterness blood feud brawl broil conflict contention controversy dispute donnybrook donnybrook fair embroilment enmity feud fight fliting fracas fuss getting even hard feelings hatred ill blood ill feeling ill will imbroglio logomachy open quarrel polemic quarrel rancor reprisal retaliation revanche revanchism revenge rhubarb rivalry row set-to sharp words slanging match snarl soreness sourness spat squabble strife sweet revenge tiff tussle vengeance venom virulence vitriol words wrangle